Many container designs provide for a funnel or spout to simplify the process of transferring liquids carried in that container to some other desired location. The need for such designs is particularly acute in the automotive area, where fuel additives, oil, lubricants, and/or other viscous liquids must frequently be delivered into vertically oriented ports of a defined size. Thus, by including a spout or funnel, the user can direct the flow and leave the arrangement in an inverted position for an extended period of time to ensure the entire amount of liquid is transferred.
One design for such a funnel and container arrangement is shown in U.S. Pat. No. 9,346,658. Here, an injection-molded unitary funnel has a narrowing, tapered cylinder terminating in a flared skirt proximate to the outlet. The taper is between 1-2 degrees, and the flared skirt is necessary to ensure the funnel has sufficient diameter for use with capless gas tanks. At the proximal end of the funnel (i.e., the end opposite the outlet/skirt), a threaded connection allows the funnel to be screwed onto a corresponding, tapped facing of the container. U.S. Pat. Nos. 4,823,238 and 9,266,707 also shows a similar, threaded funnels for attachment to a container.
U.S. Pat. No. 5,101,870 discloses a conical funnel that is carried on the top exterior of similarly shaped container. Here, the funnel conforms to the container but does not necessarily attach or engage the container when the container is being emptied.
Other telescoping or collapsible funnels, attached to or integral with containers are also well known within this field, e.g., U.S. Pat. No. 7,264,027. These funnels must be expanded prior to use, and they may be prone to inadvertent collapsing/telescoping during use.
All of the aforementioned patent publications are incorporated by reference to provide further context for the background of this invention.
One particular issue with any of the aforementioned designs relates to the lubricating nature of many fuels, additives, and the like. As a container is emptied, these liquids tend to facilitate unwanted rotation of the funnel, especially in instances where the mass of the inverted container and/or inadvertent user interactions create rotary force. In turn, this force can cause unwanted spills due to partial or complete separation of the funnel from the container.